In the construction of a reinforced concrete building, a floor is constructed, then columns and walls are constructed on that floor for supporting the next floor above it, then the next floor is constructed, and so on. Conventional practice is to erect a main crane at the center or approximate center of the building site, to be used for lifting equipment and materials up to each floor as it is added to the building. One of the pieces of equipment that is lifted and used is called a placing boom. It is a principal part of a placing boom assembly that also includes a pump for concrete and tubing through which the concrete is pumped. The placing boom is an articulated boom that supports and handles the tubing. The articulated boom is maneuvered to deliver concrete where a floor, wall or column, etc. is being constructed.
U.S. Pat. No. 3,976,092, granted Aug. 24, 1976, to Joachim Coja, Karl-Ernest von Dckardseein and Bernhard Meinker, and entitled Apparatus For The Distribution Of Concrete, and U.S. Pat. No. 4,180,170, granted Dec. 25, 1979, to Bernhard Meinker, and entitled Rotary Tower Crane For Construction Purposes With A distributor Device For Concrete, both disclose supporting an articulated concrete placement boom on the main crane. U.S. Pat. No. 3,976,092 positions an articulated concrete placement boom at an end of a horizontal boom that is on top of support tower. Pat. No. 4,180,170 discloses supporting the articulated concrete placement boom on the tower below the horizontal boom.
FIG. 4 herein is a copy of FIG. 1 in U.S. Pat. No. 4,180,170. This figure includes the reference numerals that are used in the patent. Reference is made to the patent for a detailed description of the structure shown by the patent and in part shown by FIG. 4 herein. FIG. 5 herein is FIG. 2 in U.S. Pat. No. 3,976,092. The reference numerals used in this figure are the same reference numerals that are used in the patent. Reference is made to the patent, for a detailed description of the structure that is disclosed by the patent and partially disclosed by FIG. 5 herein.
It is also known to mount an articulated concrete placing boom on top of a vertical mast that extends through aligned openings in two or more floors in the building, or is mounted on a side of the building by use of brackets, or is mounted on top of the tower that supports the main crane. A typical mast-mounted articulated concrete placement boom is manufactured by Schwing America, Inc., of White Bear, Minn. 55127. Descriptions of the Schwing articulated concrete placement boom and mounting tower arrangements are disclosed in am issue of Concrete Construction Magazine, copyrighted by The Aberdeen Group of Addison, Ill. 60101. A reprint of this article is a part of the file of this patent document. In the article, there is a description of the construction of a fourteen story housing project in which there was a need to build one floor per week. The first three floors of this building were placed from the ground with an articulated concrete placement boom that was mounted on a truck. As additional floors were added, workman anchored boom masts in openings in floors that are below the floor that is under construction. Articulated concrete placement booms were mounted on the masts. Then, with two booms working at once, crews constructed the rest of the floors. As soon as a concrete floor became set, forming crews returned to form up walls and columns. Then concrete was pumped to pour these walls and columns. Then, the support mast and placement boom were moved upwardly to be used for pouring the next floor.
According to conventional practice, at the completion of a floor, the main crane is used for lifting the materials and implements that are used for constructing the columns and walls that must be built before the support mast and the placement boom can be raised and repositioned for use in constructing the next floor. Experience has established the fact that the requirements for the service of the main crane exceed the capabilities of a standard work day. The result is overtime work for the main crane and all of the workmen that are associated with it. This overtime work is unacceptably expensive. Accordingly, the primary object of the present invention is to provide a method and apparatus which can eliminate the need for overtime use of the main crane at a cost that is small in comparison to the cost of the overtime usage of the main crane.
The present invention utilizes a telescopic turret crane that is normally mounted on a rear end portion of a truck. A suitable telescopic turret crane for use in practicing the present invention is the Model USTC 28L crane that is made and sold by USTC, Inc., of York Pa. 17401. A six page, three leaf brochure directed to USTC 28L crane is a part of the file of this patent document. Another prior art telescopic turret crane is disclosed by U.S. Pat. No. 3,985,234, granted Oct. 12, 1976, to Maurice Jouffray, and entitled Telescopic Boom For A Crane. FIG. 6 herein is FIG. 1 in Pat. No. 3,985,234. In FIG. 6, the reference numerals are the same reference numerals that are used in the patent. Reference is made to the patent for a full description of the crane that is disclosed by the patent and partially disclosed by FIG. 6 herein. A further prior art telescopic turret crane is disclosed by U.S. Pat. No. 3,481,489, granted Dec. 2,1969, to Robert E. Stauffer, and entitled Means For Extended And Retracting Boom Sections Of A Crane.
A principal object of the present invention is to provide a method of interchangeably using an articulated concrete placement crane and a telescopic turret crane for expediting the construction of a building and reducing the demand on the main crane.